122-32000 Parallax Inc, 122-32000 Datasheet - Page 182

• Manufacturer Part Number: 122-32000
• Description: MANUAL PROPELLER
• Manufacturer: Parallax Inc

Specifications of 122-32000

• Accessory Type: Manual
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: Propeller Education (PE) Kit
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

multiplied by 16 (the Clock PLL always multiplies by 16) but the 8x result would be used;
the System Clock would be 4 MHz * 8 = 32 MHz.
CON
This sets the clock mode for an external clock-oscillator, connected to XI only, and enables
the Clock PLL circuit and sets the System Clock to use the 2x result. If an external clock-
oscillator pack of 8 MHz was attached to XI, the System clock would run at 16 MHz; that’s 8
MHz * 2.
Note that the Clock PLL is not required and can be disabled by simply not specifying any
multiplier setting, for example:
CON
This sets the clock mode for an external low-speed crystal but leaves the Clock PLL disabled;
the System Clock will be equal to the external crystal’s frequency.
The _CLKFREQ and _XINFREQ Settings
For simplicity, the examples above only show
_XINFREQ
Clock’s frequency. The following is the second example with an external crystal frequency
(_XINFREQ
CON
This example is exactly like the second example above, but
frequency of the external crystal is 4 MHz. The Propeller chip uses this value along with the
_CLKMODE
command) so that objects can properly adjust their timing. See
_CLKMODE vs CLKMODE
_CLKMODE
constant containing the requested clock mode at startup (in the form of clock setting constants
that are OR’d together) whereas
(in the form of the CLK register’s bit pattern). Both may describe the same logical clock
mode but their values are not equivalent.
Page 182 · Propeller Manual v1.0
_CLKMODE = XINPUT + PLL2X
_CLKMODE = XTAL1
_CLKMODE = XTAL1 + PLL8X
_XINFREQ = 4_000_000
) of 4 MHz.
is related to, but not the same as,
setting is required to follow it so that objects can determine their actual System
setting to determine the System Clock frequency (as reported by the
– Spin Language Reference
CLKMODE
'low-speed crystal x 8
'external crystal of 4 MHz
is a command that returns the current clock mode
CLKMODE
_CLKMODE
.
_CLKMODE
settings, but either a
_XINFREQ
_XINFREQ
is an application-defined
, page 337.
indicates that the
_CLKFREQ
CLKFREQ
or